Introduce option for *NOT* connecting to cassandraQL during startup

[JiriOndrusek]

I'm working on camel-quarkus extension for CassandraQL (apache/camel-quarkus#1355)

It would be nice to use this quarkus extension.

However there is a problem, which is blocking my attempts. According to the code and quarkus blog, it is necessary to define connection parameters, which are used for connecting to CassabdraQL.

1. In my case (and I can imagine more scenarios) are connection parameters obtained dynamically. Therefore there is no way of filling application.properties in advance.
2. In my case (and I can imagine more scenarios) I'd like to connect to several CassandraQLs, which is not possible in case of hardcoded configuration in application.properties.
3. I've noticed a possibility to wait for a default connection in case that target cassandraQL is not available. (attempts for creation of the connection are repeated until there is available connection). But start of the extension is not finished and it is not possible e.g. to connect to other DBs.

IMHO it would be nice, if this extension could start also in some "offline" mode, without connecting to DB. In that case it won't be possible to inject QuarkusCqlSession. But it would be possible to create similar session(s) programatically

┆Issue is synchronized with this Jira Task by Unito

[adutra]

Hi thanks for reporting this.

Have you tried disabling eager session initialization? This could be a quick win for you.

cassandra-quarkus/runtime/src/main/java/com/datastax/oss/quarkus/runtime/api/config/CassandraClientInitConfig.java

Line 40 in c6c8b0d

public boolean eagerSessionInit;

[JiriOndrusek]

Thanks @adutra, this seems exactly as a solution for me. I'll try this parameter tomorrow.

[adutra]

In my case (and I can imagine more scenarios) I'd like to connect to several CassandraQLs, which is not possible in case of hardcoded configuration in application.properties.

For that I think we would need to expose the ProgrammaticDriverConfigLoaderBuilder bean somehow. We already create this bean internally, see here.

Maybe you could contribute a PR to expose that bean?

[JiriOndrusek]

@adutra To be honest, for my case this 'ProgrammaticDriverConfigLoaderBuilder' is not necessary. Once extension for cassandra-quarkus is used, I can use standard code to connect to cassandra using java-driver. Though It could be nice to have it for other use cases... I'll keep that in mind and look into creation of PR if time allows.

[JiriOndrusek]

@adutra Parameter eager-session-init seems to work only partially.

If parameter is set to false, the I can see in log

2020-08-25 14:32:22,621 DEBUG [com.dat.oss.qua.run.int.qua.CassandraClientStarter] (main) Not triggering eager initialization of Quarkus session at startup

application does not wait for connection, my tests are executed, but once my tests are finished, extension tries to connect again. Which means that my test execution doesn't finish.

I'm attaching trace log with my execution (there is 1 dummy test) and once camel is stopped, connection to cassandra with default values is trying to create.
trace.log

[adutra]

I think you just spotted a bug indeed. I need to investigate more, but it seems to come from the fact that we add a shutdown task to close the session, see here. I suspect that calling close() on an uninitialized proxy triggers the whole initialization procedure, and you end up with that error.

[tomekl007]

The other possible solution may be:
#75
also, this task is related to #106

[JiriOndrusek]

Hi @tomekl007,
with parameter eager-session-init is exactly solution, which I was trying to get.
Once issue #125 is closed, from my POV this issue could be closed.

[tomekl007]

Closing because it is solved by the eager-session-init and #125.
@JiriOndrusek please let me know if you need any more help.